P1175: REAL LIFE OUTCOMES OF RELAPSED/REFRACTORY DIFFUSE LARGE B CELL LYMPHOMA: A SINGLE CENTRE EXPERIENCE
Authors: I. Dogliotti, M. Clerico, F. Vassallo, S. Ragaini, V. Peri, B. Botto, C. Consoli, L. Orsucci, R. Freilone, S. Ferrero, A. Lonardo, G. De Luca, D. Ferrero, F. Cavallo
Journal: HemaSphere (2022)

Background: Nearly 40% diffuse large B cell lymphoma (DLBCL) patients relapse after first line treatment (Crump, Blood 2017) and around 15% are chemorefractory (Feugier, JCO 2005). Despite modern treatments availability, outcome of these patients remains suboptimal (Crump, Blood 2017). Aims: With the observational retrospective study STRIDER, we aimed at determining real-life outcome of relapsed/refractory (R/R) DLBCL patients. Methods: Patients were selected based on local diagnosis of DLBCL between Jan 2010 and Dec 2019 within Hematology Units at the University Hospital Città della Salute e della Scienza, Torino, Italy. R/R disease was documented by biopsy, imaging, or clinical evaluation; refractoriness was defined as reappearance or progression of DLBCL within 12 months from initial diagnosis. Demographics, laboratory, imaging, pathological and clinical data were collected retrospectively from hospital health records. Results: Overall, 413 DLBCL patients aged >18 years old were included. 151 (36%) patients had an event of relapse (n=51 patients, 12%) or refractory disease (n=100, 24%). Median age was 67 (range 21-89) years for non R/R patients (NRR) vs 72 (19-89) for R/R group (p <0.001). Advanced stage (stage 3-4: 68% vs 87%, p <0.001), baseline B symptoms (28 vs 43%, p <0.001), higher LDH level (p <0.001) and >1 extranodal site involvement (39 vs 53%, p =0.007) were linked to R/R disease, and consequently, IPI score highly affected R/R disease distribution. Kidney or adrenal involvement was less frequent in the NRR group (6% vs 11%, p =0.042). Central nervous system (CNS) involvement was present at diagnosis in only 8/413 (2%) patients, while median CNS-IPI score was 2 vs 3 for the 2 groups (p <0.001). Expression of immunohistochemical markers was not significantly different between groups. Treatment intent was curative (R-CHOP/COMP, R-Magrath, R-DA-EPOCH, MATRIX) for 391/413 (95%) patients; R/R group included reduced dose or palliative intent treatments (11 vs 2%, p <0.001). For CNS prophylaxis, intrathecal methotrexate was used in 78/413 (19%) patients, while intravenous in 22 (5%) patients. After first line completion, 99/413 (24%) patients received consolidative radiotherapy on previous bulky areas, while 4 (1%) received upfront autologous stem cell transplantation (ASCT). Interim response was not different, but end of treatment response was inferior for R/R group (p <0.001). After a median follow up of 50 months, median overall survival (OS) from initial diagnosis was NR for NRR patients, 38 months (IQR 25-64) for relapsed, 11 (5-20) for refractory patients (Figure 1). Median progression free survival (PFS) was 21 (IQR 16-30) months for relapsed vs 6 (4-9) for refractory patients. Treatments performed in II line were platinum-based (rituximab + OxDHA/DHAP/ICE/GemOx) for 50 patients (22 relapsed, 28 refractory), lenalidomide for 17 patients (5 vs 12); 14 patients were enrolled in clinical trials. Palliative intent treatments (oral chemotherapy +/- rituximab) were administered to 17 patients. II line consolidation with RT was performed in 11, ASCT consolidation in 6 patients. After II line, best response was CR in 29%, PR in 17% (ORR 45%); 45 patients received a third line, 10 more than three. Image:Summary/Conclusion: Our retrospective series confirmed good survival for NRR patients, but 36% patients were R/R after first line, with refractory patients showing a dismal outcome despite intensive treatments. Survival analyses after II line and multivariate analysis are ongoing and will be presented at the meeting.